/**
 * Copyright (c) 2011-2023, James Zhan 詹波 (jfinal@126.com).
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.jfinal.template;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.jfinal.template.source.ISource;
import com.jfinal.template.stat.Location;
import com.jfinal.template.stat.ParseException;
import com.jfinal.template.stat.ast.Define;

/**
 * Env
 * 
 * 1：解析时存放 #define 定义的模板函数
 * 2：运行时提供 #define 定义的模板函数
 * 3：每个 Template 对象持有一个 Env 对象
 */
public class Env {

    protected EngineConfig engineConfig;
    protected Map<String, Define> functionMap = new HashMap<String, Define>(16, 0.5F);

    // 代替 Template 持有该属性，便于在 #include 指令中调用 Env.addSource()
    protected List<ISource> sourceList = null;

    public Env(EngineConfig engineConfig) {
        this.engineConfig = engineConfig;
    }

    public EngineConfig getEngineConfig() {
        return engineConfig;
    }

    public boolean isDevMode() {
        return engineConfig.isDevMode();
    }

    /**
     * Add template function
     */
    public void addFunction(Define function) {
        String fn = function.getFunctionName();
        if (functionMap.containsKey(fn)) {
            Define previous = functionMap.get(fn);
            throw new ParseException(
                "Template function \"" + fn + "\" already defined in " +
                getAlreadyDefinedLocation(previous.getLocation()),
                function.getLocation()
            );
        }
        functionMap.put(fn, function);
    }

    private String getAlreadyDefinedLocation(Location loc) {
        StringBuilder buf = new StringBuilder();
        if (loc.getTemplateFile() != null) {
            buf.append(loc.getTemplateFile()).append(", line ").append(loc.getRow());
        } else {
            buf.append("string template line ").append(loc.getRow());
        }
        return buf.toString();
    }

    /**
     * Get function of current template first, getting shared function if null before
     */
    public Define getFunction(String functionName) {
        Define func = functionMap.get(functionName);
        return func != null ? func : engineConfig.getSharedFunction(functionName);
    }

    /**
     * For EngineConfig.addSharedFunction(...) only
     */
    Map<String, Define> getFunctionMap() {
        return functionMap;
    }

    /**
     * 本方法用于在 devMode 之下，判断当前 Template 以及其下 #include 指令
     * 所涉及的所有 ISource 对象是否被修改，以便于在 devMode 下重新加载
     *
     * sourceList 属性用于存放主模板以及 #include 进来的模板所对应的
     * ISource 对象
     */
    public boolean isSourceListModified() {
        if (sourceList != null) {
            for (int i = 0, size = sourceList.size(); i < size; i++) {
                if (sourceList.get(i).isModified()) {
                    return true;
                }
            }
        }
        return false;
    }

    /**
     * 添加本 Template 的 ISource，以及该 Template 使用 include 包含进来的所有 ISource
     * 以便于在 devMode 之下判断该 Template 是否被 modified，进而 reload 该 Template
     */
    public void addSource(ISource source) {
        if (sourceList == null) {
            sourceList = new ArrayList<ISource>();
        }
        sourceList.add(source);
    }
}



